Why does this acquire and release memory fence not give a consistent value?

im just exploring the use of acquire and release memory fences and dont understand why i get the value output to zero sometimes and not the value of 2 all the time

I ran the program a number of times , and assumed the atomic store before the release barrier and the atomic load after the acquire barrier would ensure the values always would synchronise

#include <iostream>
#include <thread>
#include <atomic>

std::atomic<int>x;



void write()
{


    x.store(2,std::memory_order_relaxed);

    std::atomic_thread_fence(std::memory_order_release);



}

void read()
{

    std::atomic_thread_fence(std::memory_order_acquire);

    // THIS DOES NOT GIVE THE EXPECTED VALUE OF 2 SOMETIMES
    std::cout<<x.load(std::memory_order_relaxed)<<std::endl; 

}

int main()
{

std::thread t1(write);
std::thread t2(read);
t1.join();
t2.join();
return 0;
}

the atomic varible x gives a value of 0 sometimes